Good for Tom Cruise. Don’t be misled by the title of “Edge of Tomorrow,” which sounds like some dreadful afternoon TV soap opera from the 1960s. (It seems, after all, to conflate the titles of two very real long-running afternoon soaps, “Edge of Night” and “Search for Tomorrow.”) This is the one that’s really a very creative sci-fi mashup of the semi-obscure “The Americanization of Emily,” “Starship Troopers” and, most importantly, the smash-hit “Groundhog Day.” It’s one of the smarter sci-fi films we’re likely to see this summer.

Make no mistake. This is Cruise’s baby. His career, as he steers toward his 51st birthday on July 3, is at a very tender stage. The early 50s are not an especially good age these days to be an action movie star whose usual stock-in-trade is hopeless boyishness. Being a convincing grown-up has been a ticklish career problem for more than a decade. One of the major creative figures in Tom Cruise Inc. helping Cruise in this era is the very clever screenwriter Christopher McQuarrie who, let’s not forget, won a well-deserved Oscar for his screenplay for “The Usual Suspects.” He’s been writing a lot of Cruise’s recent films in his career transition toward “maturity” (i.e. only nine years from 60) and, with varying results, the evidence is that McQuarrie’s got a very deep inherent understanding of Cruise’s problems at this stage of professional life.

That boyishness thing? Not so hot for a 51-year-old guy. But steal some ideas from actor James Garner in Paddy Chayefsky’s great script for the 1960s near-classic “The Americanization of Emily” and you’ve got a great way to handle maturity when it isn’t really maturity at all. You turn Cruise into a chicken-hearted major named Cage in the Army’s public relation corps at an unspecified future time when the human race is fighting a war against some ugly extraterrestrials with far too many tentacular legs and the land speed of NASCAR pace cars when they’re on the attack. They’re called Mimics.

Making Cruise a wise guy, a coward and a self-important weasel in an Army uniform is a very clever way of dealing with the boyishness that still clings to that ultra-famous face, despite the whisper of puffiness and wrinkles you can see hiding in there and waiting patiently to emerge.

The critters from outer space are on their way to conquering Europe, just like the Nazis in “The Americanization of Emily.” Things aren’t looking good for us humans. So there’s a Normandy-style D-Day in France called Operation Downfall planned. Our lily-livered major wants no part of it because he suspects, quite rightly, it will be a slaughter for the WDF (World Defense Force.) A fed-up WDF general (Brendan Gleeson) reacts to the coward’s attempted extortion by clapping handcuffs on him and shipping him off to the front with zero combat training.

And this is where it gets a bit tricky. Stay with me. It seems there are two higher-grade Mimics besides all the yucky swarming infantry grunts with all their tentacles waiting to get shot off. They’re called “Alphas” and, the big shot Mimic of them all, the one “Omega.”

The Alpha creatures have the ability to control time. Kill one of them and you’re going to have to keep on reliving the period of time leading up to the event and afterward, right up to your death. Get lucky, though, find the Omega and kill him and it’s all over but the shouting. You’ve saved humankind from yet another reptilian army of oozy extraterrestrials.

Our boy Cage (Cruise) has the misfortune to kill an Alpha, almost by mistake. Ergo, here comes the central “Groundhog Day” portion of the movie where he has to keep reliving over and over the same story until he starts making progress toward turning the big Omega M imic into cat food.

There’s your movie except for one more clever little wrinkle among many in this unusually creative sci-fi fantasy: Cage’s big coach in all military matters, his partner in military derring-do and his (sort-of) romantic interest is the most decorated soldier in the WDF, a woman named Rita, whose nickname is “the Angel of Verdun” (a nicely sly little reference to a battle between the Germans and the French during World War I.) So Cage and Rita (Emily Blunt) are the ones searching for the Omega who, naturally enough, is hiding someplace visually recognizable, like, say, beneath the controversial glass Pyrmaid at the Louvre.

It’s so much niftier and more creative than all the summer sci-fi that usually gives us debased science and pretty duncey fiction that you can’t help being grateful to Cruise. His director is Doug Liman, who knows a thing or two about action movie kinetics (as in a couple of “Bourne” movies) and about humor too (his first attention-getter was “Swingers”). In truth, this movie could have used more of the latter. Not only are war movies liable to drift into self-righteousness without it but Cruise, as he proved forever in Ben Stiller’s “Tropic Thunder,” can be riotously funny when everyone temporarily forgets he’s Tom Cruise.

If you ask me, the sci-fi track record of this poster boy for Scientology could be far worse – those two films he made with Steven Spielberg, “War of the Worlds” and “Minority Report” and now this thing which admittedly steals from a lot of movies but, you have to admit, pretty good and unusual ones. It’s too creatively upmarket to clean up at the box office of the megaplex but it’s nothing but good news that it’s there.

EDGE OF TOMORROW

3½ stars

Starring: Tom Cruise, Emily Blunt, Brendan Gleeson

Director: Doug Liman

Running time: 113 minutes

Rating: PG-13 for some language and a lot of sci-fi creature violence.

The Lowdown: A chicken- hearted Army major keeps re-living battles against extra-terrestrials and eventually turns heroic.